Anyone can identify as a feminst, it’s a free country.
Depends I suppose on working out what you see ‘feminist’ as meaning.
If you see it as about the equality of the sexes – well for a start, if you’re pro mixed gender bathrooms you already have an interesting conflict in your feminism, since this pro position ignores the issues this presents around safeguarding, the massive issues of women who have been abused, raped and assaulted and are highly distressed at the idea of sharing private spaces of undress with male bodies, and women whose culture and religion will mean not being able to enter any gender neutral or ‘inclusive’ toilet or changing room. Those are all pretty massive issues of equality, inclusion and the specific difficulties facing (only) the female sex that feminism should be considering.
If you’re ok with mixed sex inclusion in things like Girl Guides you have another issue there, as you’re agreeing that female born people shouldn’t have the right to meet and have any provision apart from male born people, and that there is no impact on female born people and their opportunities and even how they talk and play and interact as children, if male bodied children are present. Huge issues specific to females.
Other whacking female body issues: pregnancy, periods, FGM, 98% of sexual assaults being committed by men, needing to share prison provision with convicted rapists and paedophiles – if you’re identifying as feminism being the equality and rights of women those things probably ought to be of interest you. Otherwise your feminism runs the risk of actually being about suppressing the voices and the vulnerable groups of female born people to please and pacify male born people, some of whom have used the word ‘feminism’ to colonise and shift the focus away from women from inside, and encourage other women to believe that focusing on women's bodies, women's rights and women's equality is somehow selfish and wrong.
Female socialisation: another big feminist issue.
As pp says, YMMV. Depends on what you see 'feminism' as being.